1. Field of the Invention
The present invention relates to an information processing apparatus such as a personal computer and its control method for cooling inside the apparatus with a cooling fan.
2. Related Background Art
On an information processing apparatus such as a personal computer, a cooling mechanism is generally mounted for cooling the entire apparatus or a CPU. As a cooling mechanism for this purpose, there is a heat sink or a cooling fan. As a heat release value is increased due to an improvement of a processing speed of the CPU in recent years, mainly a cooling fan or a heat sink with a cooling fan is used. If a cooling fan is stopped due to its failure during forced air-cooling with the cooling fan, a CPU or other electronic components may be damaged by heat.
Therefore, there is an information processing apparatus which monitors a temperature inside the apparatus, notifies the CPU that the temperature has reached a predetermined or higher level when detecting it, and disconnects a power supply unit with a control of the CPU.
In this type of an information processing apparatus, however, the power supply unit can be disconnected only under the condition that its software continues the normal operation, and therefore the power supply from the power supply unit cannot always be stopped at an abnormal temperature.
Accordingly to remove this disadvantage, as shown in FIG. 7, there has also been suggested an information processing apparatus in which a power supply unit 9 can be stopped even if a CPU 2 is not normally operating, by supplying a temperature abnormal signal from a temperature sensor 10 not only to the CPU 2 but to a counter 3, directly driving the counter 3 responding to the temperature abnormal signal from the temperature sensor 10, and halting the power supply unit 9 responding to a time-out signal from the counter 3 in addition to a control signal from the CPU via an OR circuit 8.
The above-described information processing apparatus, however, halts the power supply unit when detecting an abnormal temperature, and therefore if a cooling fan is stopped by a failure, a preparation for disconnecting the power supply unit is started after the temperature is increased up to a predetermined or higher level. Accordingly its electronic components may be damaged by heat before the power supply unit is disconnected.
On the other hand, if a temperature determined to be abnormal is set to a relatively low level so as to make allowance for the above increase of the heat, an upper temperature limit is forcibly lowered unnecessarily on the information processing apparatus as a condition under which the apparatus can be installed.